Ventilated bus bar



July 25, 1939- R. W. sHoEMAKl-:R ET AL 2,167,378 I VENTILATED BUS BAR Filed May l0, 1937 2 Sheets-Sheet l El @zg/1 R. W. sHoEMAKx-:R ET Al.

Juy 25, 1939.

VENTILATED BUS BAR Filed May l0, 1937 2 Sheets-Sheet 2 Patented July 25, 1939 UNITED STATES PATENT OFFICE Woodbury, C

onn., assi xnors to Chase Brass & Copper Co. Incorporated, Waterbury, Comi., a corporation o! Connecticut `Application May 1o;1937, serial No. 141,647

1l Claims.

This invention relates to an improvement in bus-bars, and more particularly to bus-bars which are constructed and arranged to permit the passage of air therethrough to dissipate heat devel oped under operating conditions.

Heat developed in ventilated bus-bars as the result of the passage of current therethrough may be dissipated mainly in two ways, i. e., by the wiping action of air currents (convection) and by radiant heat emanation. The bright surfaces of copper and other high electroconductive materials, however, are not usually efticient as regards radiant heat emissivity, and if rendered eilicient in this respect by surface treatments, the radiant heat tends to be shuttled back and forth between opposing surfaces without materially lowering the temperature of the bus-bar structure. Thus, with respect to the inner surfaces of hollow busbar structures or the opposed surfaces of the laminae or component elements of composite busbars, but a relatively small amount of heat may be effectively dissipated in the form of radiation.

The main object of the present invention is to` provide a ventilated bus-bar structure having superior capacity for dissipating heat developed by the passage of current therethrough to thus enable the bus-bar to function with greater ei'- iiciency.

A further object of the-present invention is to provide a bus-bar structure having superior capacity for dissipating radiant heat.

Another object is to provide a bus-bar structure having superior means for dissipating radiant heat by convection.

With the above and other objects in view, as will appear to those skilled in the art from the present disclosure, this invention includes all features in the said disclosure which are novel over the prior art and which are not claimed by me in a separate application. A

Inthe accompanying drawings, in which certain modes of carrying out the present invention are shown for illustrative purposes:

Fig. 1 is a broken plan view of a portion of a bus system composed of bus-bars embodying the present invention;

Fig. 2 is a broken perspective view of a portion of the tubular bus-bar structure;

Fig. 3 is a fragmentary top or plan view thereof;

Fig. 4 is a broken perspective view showing the tubular bus-bar prior to the introduction thereinto of thel radiant-heat-absorbing member;

Fig. 5 is a similar view of the radiant-heat-absorbing member;

Fig. 6 is a transverse sectional view showing the radiant-heat-absorbing member as transversely bowed for its ready introduction into the hollow bus-bar;

Fig. 7 is a transverse sectional view illustrat-A ing another form of radiant-heat-absorbing mem- 5 ber or partition;

Fig. 8 is a longitudinal sectional view thereof taken on the line 8 8 of Fig. 7;

Fig. 9 is a perspective view oi the radiant-heatabsorbing member of Figs. 'l and 8; l

Fig. 10 is a view mainly in side elevation and partly in vertical section of another form of tubular bus-bar structure embodying the present invention;

Fig. 11 is a transverse sectional view thereof 16 taken on the line l I-II of Fig. 10; and

Fig. 12 is a transverse sectional view of still another form of bus-bar structure embodying the present invention.

The particular bus-bar 20 illustrated in Figs; 20 1 to 6 inclusive is a one-piece tube of rectangular form in cross-section and is preferably formed oi' drawn-copper or other high electro-conductive material. 'I'he tubular bus-bar includes a ilat top-wall 2|, a flat bottom-wall 22, and oppositely- 25 located :dat side-walls 23 and 24.

Along the transverse center of its top-wall 2i, the bus-bar is formed with a longitudinal series of spaced-apart air-egress ports or passages 25, and, similarly, the bottom-wall 22 is formed with 30 a llongitudinally-extending series of air-ingress ports or passages 26.

'Ihe upper surface of the bottom-wall 22 of the tubular bus-bar 20 is formed centrally with a longitudinally-extending upwar d'1 y-opening 35 groove 21 receiving the lower edge of a plateor partition-like radiant-heat-absorbing member 28, which has its upper edge seated in a downwardly-opening longitudinally-extending groove 29 formed in the under face of the top wall 2| of the tubular bus-bar 20. The radiant-heatabsorbing plate or partition 28 is, in the instance shown, formed of non-ferrous metal such as copper, andl is provided on each of its respective opposite sides with a radiant-heat-absorbing coat- 45 ing 30, which coating may be in the form oi' a black paint, cupric oxide, or other material having a high factor of radiant heat-absorption. If desired, instead of employing a metallic plate or partition, a plate or partition of black vulcanized ilber or the like may be employed, in which case the coating such as 30 is not required. Other non-metallic materials which may be mentioned as suitable are molded mica, phenolic resins, etc.

For convenience in assemblingthe member 28 55 within the bus-ber proper zo, the said member may have imparted to it an initially-transverse curvature, as illustrated in Fig. 6, and after lt has been drawn lendwise into position within the said bus-bar, it may be straightened out by any suitable means into thel form shown particularly well in Fig. 2, to .thus seat its respective opposite edges in the ,grooves 21 and 29.4

To render the inner surfaces of the walls 2i to 24 inclusive of the bus-bar 20 more effective in emitting radiant heat, it is preferable to provide thesame with a coating 3| of suitable material such, for instance, as light gray transformer paint or other suitable material, for the purpose of which there are numerous recognized in the heating art.

As thus constructed and arranged, when the bus-bar structure becomes heated by the passage of current therethrough, radiant heat, represented by the broken-line arrows in Fig. 2, will be emitted by the inner surfaces of the walls 2| to 24 inclusive of the bus-bar 20, and will impinge upon and be largely absorbed by the radiantheat-absorbing member 28, and in the main will not be reflected back toward their point of origin.

The current of air entering through the air-in gress ports 26 in the bottom-wall 22 and passing upwardly and outwardly through the air-egress ports 25 will wipe over, so to speak, the' opposite surfaces of the member 28, as indicated by the full-line arrows in Fig. 2, and thus continually remove the heat absorbed, as described, by the member 28.

Tests under a 60-cycle 3200-ampere load have shown that a 5-inch-square copper bus-bar of the type shown in Figs. 1 to 6 inclusive has a temperature rise of only about 25.5 F. when the average room temperature was about '72.5 F. The same tube provided with only the air-ports 25 and 26 showed, under the same conditions, a temperature rise of about 39 F.

From the foregoing, it will be seen that by means of the present invention, the temperature of a bus-bar structure under operating conditions may be maintained at a relatively-low level and thus at a relatively-high degree of electro-conductive erliciency.

In Figs. '7 to 9 inclusive. a one-piece tubular bus-bar 32 is shown which is preferably formed of copper or other high electro-conductive material, and like the bus-bar 20, previously described, it includes a top-wall 33, a bottom-wall 34, and complementary side-walls 35 and 36.

Also, like the bus-bar structure of Figs. 1 to 6 inclusive, the bus-bar 32l is provided in the lateral center of its top-Wall 33 with a longitudinal series of air-egress ports or passages 31 arranged in line with a longitudinally-spaced series of airingress ports or passages 38 formed in the bottom-wall 34. y

Installed within the bus-bar 32 substantially parallel with and midway between the respective opposite side-walls 35 and 36 thereof is a radiant-heat-absorbing member 39 provided along its respective opposite edges with a plurality of stabilizing-tongues 40, slightly tapered and spaced apart to conform to the longitudinal spacing of .the ports 31 and 38 and adapted to extend there- Y into, as shown in Figs. '1 and 8. To permit the ready installation of the member 39, the same may be transversely bowed, as indicated by broken lines in Fig. '7, then forcibly straightened out, or permitted to straighten out under its own resiliency, to assume the position indicated by full lines in Fig. '7. 4Each of the respective opposite faces of the plate-like radiant-heat-absorbing member 38 is provided with a coating 4I, preferably of dark coloration and having superior capacity for the absorption of radiant heat and for the dissipation of heat by convection than have the interior surfa'ces of the bus-bar 32, which surfaces are preferably provided with a continuous coating 42 providing high radiantheat emissivity.

In Figs. 10 and 11 is illustrated a bus-bar 43 which is of rectangular form in cross-section and positioned so that two of its apices are in vertical alignment, one over the other. The upper apex of the bus-bar 43 is provided at longitudinallyspaced points with air-egress ports or passages 44 through which outwardly pass air currents entering the `bus-bar through air-ingress ports or passages 45 drilled' orv otherwise formed in the lower apex of the bus-bar 43 in longitudinallystaggered relationship with respect to the said air-egressports 44.

The interior of the bus-bar 43 is provided with a surface 46 having a high degree of radiantheat emissivity as compared to therespective opposite faces 41 of a transversely-corrugated resilient radiant-heat-absorbing member or partition 48. The surfaces 41, just referred to, of the member 48 are characterized by a superior capacity for absorbing radiant heat emitted by the surfaces 46, so that such absorbed radiant heat may be readily carried E by air currents which wipe thereacross in passing through the bus structure from the air-ingress ports 45 outwardly to the air-egress ports 44.

In Fig. 12 is illustrated a ventilated bus-bar structure of laminated form, which includes a series of spaced-apart conductor-plates or bars 49 providing-between them a series of verticallyextending Ventilating-passages 58. The said conductor-plates or bars 49 are held in the spaced relationship referred to by having their upper edges seated in notches i formed in the under faces of an upper clamp-member 52 and their lower edges seated in( upwardly-opening notches 53 formed in a lower clamp-member 54 whichis rigidly coupled to the complemental upper clamping-member 52 by suitable bolts 55.

Mounted centrally in each of the Ventilatingpassages 50 of the bus structure of Fig. 12 and held in place by having its respective opposite structure, and particularly radiant heat.

The invention may be carried out in other specific ways than those herein set forth without departing from the spirit and essential characteristics of the invention, and the present embodiby superior capacity for dissipation ofl heat developed in the bus-bar ments are, therefore, to be considered in all rel spects as illustrative and not restrictive, and all changes coming within the meaningand equivalency range of the appended claims are intended tb be embraced therein.

We claim:

l. A bus-bar structure having a Ventilating` passage therethrough and provided with an inner radiant-heat-emitting surface and an inner radiant-heat-absorbing surface spaced from each other and the latter surface having greater heat-absorbing properties than the former and being positioned in the bus-bar structure so as to be swept over by air currents passing through the Ventilating passage therein to cause the said air currents to remove by convecvtion the'radiant heat absorbed by the said radiant-heat-absorbing surface from the said radiant-heat-emitting surface. p

3. A bus-bar structure having a Ventilating passage therethrough and having an inner surface coated with a radiant-heat-emitting material, the bus-bar also having an inner surface spaced from the first-mentioned surface and provided with a radiant-heat-absorbing coating having greater heat-absorbing properties than the said heat emitting-surface and positioned in the bus-bar structure so as to be swept over by air currents passing through the Ventilating passage therein to cause the said air currents to remove Iby convection the radiant heat absorbed by the said radiant-heat-absorbing coating from the said radiant-heat-emitting material.

4. A bus-bar structure having a Ventilating passage therethrough and provided with an inner radiant-heat-emitting surface and an inner radiant-heat-absorbing surface spaced from each other and the latter surface being positioned in the bus-bar structure so as to be swept over by air currents passing through the ventilating passage therein to cause the said air currents to remove by convection the radiant heat absorbed by the said radiant-heat-absorbing surface from the said radiant-heat-emitting surface the radiant-heat-emitting surface having a coating of radiant-heat-emitting material of relatively-light coloration, and the radiant-heatabsorbing surface having a radiant-heat-absorbing coating of relatively-dark coloration.

5. A bus-ban structure having a Ventilating passage therethrough; said bus-bar structure including an electro-conductive member having an inner radiant-heat-emitting surface; and said bus-bar structure also including a radiantheat-absorbing member organized with said electro-conductive member and having lgreater heat-absorbing properties; the said radiantheat-absorbing member being located in position to receive and absorb radiant heat from the said inner surface ofthe electro-conductive member of the bus-bar structure and being arranged in exposed relation to be swept over by air currents flowing through the said Ventilating passage to cause the said air currents to remove by convection the radiant heat absorbed by the radiantheat-absorbing member from said inner radiantheat-emitting surface.

6. A bus-bar structure having a Ventilating passage therethrough; said bus-bar structure including an electro-conductive member having an inner radiant-heat-emitting surface; and said bus-bar structure also including a radiantheat-absorbing member having a radiant-heatabsorbing coating having greater heat absorbing properties than the said heat emitting-surface; the said radiant-heat-absorbing member being organized with the said electro-conductive member in position to receive and absorb radiant heat from vthe said inner surface of the electro-conductive member of the bus-bar structure and being arranged in exposed relation to be swept over by air currents flowing through the said Ventilating passage to cause the said air currents to remove by convection the radiant heat absorbed by the radiant-heat-absorbing member from said inner radiant-heat-emitting surface.

7. A bus-bar structure having a Ventilating passage therethrough; said bus-bar structure including an electro-conductive member having an inner surface provided with a radiant-heatemitting coating; said bus-bar structure also including a radiant-heat-absorbing member having a radiant-heat-absorbing coating having greaer heat-absorbing properties than the said heat emitting-surface; the said radiant-heatabsorbing member being organized with the said electro-conductive member in position to have its coating receive and absorb radiant heat from the said radiant-heat-emitting coating of lthe electro-conductive member of the bus-bar structure and being arranged in exposed relation to be swept over by air currents owing through the Ventilating passage therein to cause the said air currents to remove by convection the radiant heat receivedby the said radiant-heat-absorbing coating from the said radiant-heat-emitting coating.

8. A bus-bar structure having a Ventilating passage therethrough; said bus-bar structure including an electro-conductive member having an inner radiant-heat-emitting surface; said .y

bus-bar structure also including a radiant-heatabsorbing member; the said radiant-heat-absorbing member being organized with the said electro-conductive member in position to receive and absorb radiant heat from the said inner surface of the electro-conductive member of the bus-bar structure and being arranged in exposed relation to be swept over by air currents iiowing through the said Ventilating passage to cause the said air currents to remove by convection the radiant heat absorbed by the said radiantheat-absorbing surface from the said radiantheat-emitting surface; the inner radiant-heatemitting surface being provided with a radiantheat-emitting coating of relatively-light coloration and the radiant-heat-absorbing member being provided with av radiant-heat-absorbing coating of relatively-dark coloration.

9. A bus-bar structure having a Ventilating passage therethrough and having an inner surface provided with a radiant-heat-emitting coating; a radiant-heat-a-bsorbing partition having a radiant-heat-absorbing coating having greater heat-absorbing properties than the first said coating and installed in the bus-bar structure intermediate opposed walls thereof in position to have its coating receive and absorb radiant heat from the radiant-heat-emitting coating of the passage therethrough and also having an inner radiant-heat-emitting surface; a radiant-heatabsorbing partition installed in the bus-bar structure intermediate opposed walls thereof in position to receive and absorb radiant heat from the inner surfaces of the bus-bar structure and to be swept over by the air currents flowing through the ventilating passage therein; the inner radiant-heat-.emitting surface being provided with a radiant-heat-emitting coating of relatively1ight coloration and the radiant-heatabsorbing partition being provided with a radiant-heat-absorbing coating of relatively dark coloration. i

11. A one-piece tubular bus-bar having a longitudinal series of spaced-apart air-ingress ports in its lower face and also having a similar series of air-egress ports in its upper face; and a radiant-heat-absorbing partition installed within the bus-bar structure intermediate the respective opposite side-walls thereof and in line with both the said air-ingress and air-egress ports inposition to receive and absorb radiant heat from the interior of the tubular bus-bar, and in position to be swept over'. bythe air currents owing between the said air-ingress and air-egress ports.

l 12. A one-piece tubular bus-bar having a longitudinall series of spaced-apart air-ingress ports in its lower face and also having a. similar series of air-egress ports in its upper face; a partition having each of its respective opposite faces` provided with a radiant-heat-absorbing coating and installed .in the bus-bar structure intermediate the respective opposite side-walls thereof and in line with both the said air-ingress and air-egress ports in position to be swept over by the air currents flowing `between the said ports.

13. A bus-bar structure comprising: a series of laterally-spaced-apart conductor-bars providing Ventilating passages therebetween; and a radiant-heat-absorbing member positioned laterally intermediate two of the said conductorbars and having greater heat-absorbing properties than the latter in position to receive and absorb radiant heat from the adjacent surfaces of the said conductor-bars and in position to be swept over by air currents passing therebetween.

14. A bus-bar structure comprising: a series of laterally-spaced-apart conductor-bars providing Ventilating passages therebetween; and a radiant-heat-absorbing member positioned laterally intermediate two of the said conductorbars in position to receive and absorb radiant heat from the adjacent surfaces of the said ccnductor-bars and in position to be swept over by having vic 

